Bias insulating tape



Nov. 18, 1930. H. 1. DIAMOND 1,781,895

BIAS INSULATING TAPE Filed Dec. 13; 1927 v A ,Mx

r l z Patented Nov. 18, 1930 HAARRY I. DIAMOND, F ATLANTA, GEORGIA BIAS INSULATING TAPE Appneatien mea December 1s, 1927. semil Ne. 239,687'.

The present invention relates to an insulating tape, more especially to a bias insulating tape susceptible of a number of uses, .particular among which is as/an in- 5 sulating wrapping for electrical conductors. Tape of the character now commonly used, includes in its structure astraight cutfabric strip, thatvis a fabric strip with its longitudinal edges running parallel with ,its warped threads and its transverse threads n lying at substantially right angles to the i edges. A K

. In the use of insulating tape, it is usual to rst wind about electrical conductors strips of highly insulated material, such as a soft 'adhesive rubber or gutta percha compound, and afterwards to cover this insulation by winding about it a strip of fabric having friction material u on its faces. This ractice is objectionag iiappens that the work-men'will omit the first winding and use only the strip of e fabric capable of insulating to a relatively small degree. l further objection lies in the fact that the first winding being of a soft or plastic material cannot be wound tightly, as it will not withstand a substantial pulling strain to effect` a tight winding free from bulges, puckers or folds.

It has, therefore, been found desirable to combine the two strips or windings 'heretofore used into one unitary tape, the fabric stri of which will reinforce and give body to t e soft plastic strip enabling it to .be wound tightly.

The use of either type of tape, above delined, however, does not readily lend itself Ain wrapping curved or irregular"surf aces or 40 in wrapping in 'a spiral, as about spliced ends of two electrical conductors because -it does. not have suflicient stretch or elasticit to prevent bulging or puckering thereo It is desirable to have thedwrapping smooth and free from puckers or folds, not onl to make a neat appearance but to provi e .a tight even wrappingilwhich will exclude air and moisture from t e interior of the wrappin j Q0 "Ilse nventcn, therefore, has for its ob le, because it often .videa bias :tape that maybe readily torn transverselyfby the workmen in order to sever the desiredv portion for use from the supply or roll.

It is a further object of the invention to ce provide a bias insulatin tape of the unitary character, above define where a'temporary `protecft1ve strip or layer is superimposed upontthe soft adhesive insulating la er, this protective strip being..of such a c aracter that the same may be torn by the hand simultaneously with the bias strip of the tape, said strips being so associated with respect` to each other that said tearing Will produce a projecting tab, ut the torn or severed 70 edges, facilitating the ready separation of the tape proper from the temporary protect-ive strip. v The other objects and features of invention will appear from sundry detailst of construction, operation and arrangement of parts hereafter specifically described and pointedout in the appended claims.

In the drawings which show the invention as at present devised:

Figure 1t shows one of the broad faces of a tape made in accordance with the invention with its several layers broken away to show in succession a small portion of the various layers.;

Figure 2 is a longitudinal section through the tape showing Figure 1, the layers being greatly'exaggerated in thickness forthe purpose of clarity;

Figure 3 is a transverse sectional view of 90 the tape taken substantially on the line 3 3 of Figure 1. e

. Figure 4 is a rospective view showing the act of tearing t e tape transversely; and v Figure 5 is a plan view of a piece of the 95 tape which has been torn in the manner shown in Fi ure4.

Re erring in detail to the drawings, T desi ates the tape of the invention built up w w include. a, Strip 10 of fabric cut on the bias 100 having one face coated with a friction mar/-V terial 11,"`and having united thereto on its other face, preferably by pressure, a layer strip v12 of rubber or .any nother approved highlyadhesivefand highly insulating material. It is to be understood that it is within the purview of this present invention to have both faces of the fabric 10 skin-coated with the friction material 11 and the insulating layer 12 applied directly to one of the friction coated surfaces. To the outer or highly adhesive layer 12 is applied a protective strip 13, preferably in the form of a sized fabric, known as Holland, to which the layer 12 will only moderately adhere, the` commonly used, as the layer 12 forms a highly insulating covering and the fabric layer 10 forms the'covering or protective layer of the insulating wrapping, it being understood, of course, that this tapev is usually wound VKin a helical form with its edges slightl overlapping and is pulled'tightly during tie winding operation to close all cevices and interstices to exclude air and moisture.` It will be appreciated that the fabric layer 10 willwithst nd the strain of the pull inci- Q, 'dent with the ight wrapping of the tape in the manner described which would not be sustained bya strip of rubber of sufficient softness as is'required to obtain a /proper contact between-the object wrappedand the insulating layer.

As hasibeen stated above, a tape of the ordinarystraight cut fabrics will not admit of a smooth, even wrapping inI helical form or around irregular surfaces as may occur in the spliced ends of electrical conductors or the like, -and for .this reason applicant4 provides his fabric layer 10 in the form of abiasfstrip..

However, the difficulty in the use of bias strips for insulating tape has been that it strongly resists tearing tothe extent of making the use of a cutting tool necessary, which the workman finds'` inconvenient to handle, and consequently bias insulating tapesvhave notv beenregarded as practical.

` It has been found that if the bias strip 10 1 is cut so that one`set of threads is disposed at an angle between 5 and 40 relative to the longitudinal edge of the strip, the same may be torn readily by the hand without any inconvenience, and at the same time the tape will have sufficient elasticity, due to its bias,

to permit 4it to be pulled andV stretched around tary in structure,

irregular surfaces in a manner that will roduce the desired and proper smooth win `ng. The best result can be obtained with the tape when the fabric 10 has been cut on a bias so that one set of the threads is disposed at an angle. between 10 and 25 relative to the longitudinal edge of the strip, although any 4degree between 5 and40 will give satisfactory results.

With tapes as herein shown, a temporary protective strip 13 is required as a practical measure and, when this strip is of a fabric,

the same-is not bias but straight cut, thereby Y offering no hindrances to the manualtearing of .the tape in a transverse direction, but asslsts in effecting the initial Aportion of the @tear in the fabric 10, which is simultaneously made therewith. Furthermore, by virtue of the fabric 10 being bias and the strip 13 being straight cut, this tearing of .the tape,

as shown in Figure 4,- results in either thetorn end of the strip 10 or strip 13 projecting beyond the other, thus forming a tab 15 which facilitates the separation of the tape proper T from the protecting strip 13.

I nsula'ting tapes are generally passed through a calender either to friction coat them or to apply a thicker layer of insulating material, suchas the layer 12. It is found that to employ a usual bias-cut fabric wherein the threads are disposed at an angle or 45 relative to the longitudinal edge of the strip, the fabric becomes distorted while passing through-thev,calender, making the resultant vstri very inconvenient to handle and undesira le in a number of respects. Therefore, by reducing the angle of one set of the threads of the strip 10 a more perfect result is obtained while calendering the same, andfthe best result as before stated is obtained when oneset Vof the threads is disposed at an angle between 10 and 25 relative to the longitudinal edge ofthe strip. However, in the drawings the fabric is shown as being cut on a bias wherein one set of the threads is disposed at an angle of 17 relative to the longitudinal edge of the fabric.

It will be manifest from the above that a very noyel, efficient and. inexpensive insulating tape has been providedpwhich is unieliminating the necessity of the two windings now required to make a proper insulated covering for electrical conductors, and which also has incorporated in ithis structure means permitting the tape to transversely when desired, and will also rothe4 vtemporary protectlve strip from the tape as a vide a tab facilitating the separation o result of said tearing.

While the tape shown herein is provided ,with the rubber insulating layer 12, it is understood that this invention is not limited to this disclosure and may be used in connection solely-with ordinary friction tape with or without the temporary protective covering or strip 13.` It is also preferred in the manufacture of this invention to produce the same in continuous unbroken strips instead of a p-lurality of bias strip sections joined together at their ends. N Y

It is also clear that, While this invention has been disclosed in connection with socalled insulating and friction tape, it is likewise useful in connection with surgical adhesive tape, and it is to be understood that my invention may include this and other'tapes of a similar nature.

What is claimed is:

1. A wrapping tape comprising a bias-cut Vfabric strip, one set of the threads of said fabric being disposed at an angle between 5 and 40 relative to the longitudinal edge of the strip, whereby the strip may be readily manually torn and pulled smooth when wound irregularly or about irregular surfaces, and an adhesive material on said strip.

2. A wrapping tape comprising a stretchable bias-cut fabric strip, one set of thethreads being disposed at an'angle of about 17 relative to the longitudinal edge of the strip, whereby the strip may be manually torn and pulled smooth when wound irregularly, and an adhesive material on said strip.

3. A wrapping tape comprising a stretchable adhesive strip, and a protective covering strip on one face of said adhesive' strip, said adhesive strip being ofAbias-cut fabric having one set of its threads disposed at an angle between 10 and 25 relative to the longitudinal Y edge of'the strip and said protective strip being straight cut.

4. A wrapping tape vof the kind described comprising a bias-cut stretchable` adhesive strip having one set of its threads disposed at an angle between 5 and 40 relative to the longitudinal edge of the strip, a protective covering strip of straight cut fabric on the adhesive material on said strip whereby said strip may be manually torn transversely,

Awhereby a projecting tab is provided at said severed ends as a result of said tearing to facilitate the separation of said strips.

5. A wrapping tape of the kind described comprising a bias-cut stretchable insulating strip having one set of fits threads disposed at an angle of about 17 relative to the longitudinal edge of the strip, a protective strip on said strip, said protective strip being straight cut.

6. An insulating tape comprising a biascut fabric strip having one set of threads disposed at an angle between 10 and 25 relative to the longitudinal edge of the strip, whereby the same Ymay be pulled smooth when wound irregularly and manually torn in a/transverse direction, and an insulating material on said strip.

7. `An insulating tape comprising a bias- Y cut fabric strip having one set of threads disposed at an angle between 10 and 25 relative to the longitudinal edge of the strip, whereby the same may be pulled smooth when wound irregularly and manually torn in a.

transverse direction, an insulating material on said strip, and a temporary protective covering strip of straight cut fabric superposed on one surface of said bias cut strip. i

8. An insulating tape comprising a bias-cut the longitudinal edge of the fabric, said fabric having coatings of adhesive material and rubber supposed thereon.

10. An insulating tape comprising a biascut fabric having one set of the threads disposed at an angle between 10 and 25 relat-ive to the longitudinal edge of the fabric, said fabric having coatings of adhesive material and rubber superposed thereon.

11. An insulating tape comprising a biascut fabric having one set o f threads disposed at an angle of about 17 relative to the longitudinal edge of the fabric, said fabric having coatings of adhesive material and rubber superposed thereon.

12. An insulating tape comprising a biascut fabric having one set of the threads disposed at an angle between 5 and 40 relative tothe longitudinal edge of the strip, a coating of friction material on one Side thereof, a coating of rubber on the other side thereof, and a removable protective covering on said rubber coating.

13. An insulating tape comprising abiascut fabric having one set of the threads disposed at an angle of about 17 relative to the longitudinal edge of the strip, a coating of friction material on one side thereof, a coating of rubber on the other side thereof, and a removable protective covering on said rubber coating.

signature to this specification.

HARRY I. mAMoND;

iso 

